1. Field of the Invention
The present invention relates to an alarm apparatus for use in a shoplift preventive system or the like. More particularly, the invention relates to a self-sounding tag alarm apparatus having a tag type body attached to a commodity and automatically operable to sound an alarm when an attempt is made to steal the commodity.
2. Description of the Related Art
Conventionally, this type of self-sounding tag alarm apparatus is used in a shoplift preventive system employing a detector having a gate (antenna) of the electromagnetic induction coupling type or the like.
In the shoplift preventive system, the self-sounding tag alarm apparatus is attached to a commodity, e.g. an article of clothing, by means of a wire, pin, adhesive tape or the like, and placed in a salesroom. When a shoplifter, in an attempt to take the commodity without paying, passes through a gate adjacent a cashier's counter, the self-sounding tag alarm apparatus attached to the commodity receives an electromagnetic wave of a particular frequency from the gate. Then, the alarm apparatus resonates with the electromagnetic wave, and sounds an alarm. If a shoplifter removes the self-sounding tag alarm apparatus from the commodity before walking off with the commodity, the alarm apparatus detects detachment of the wire or the like and gives an alarm.
In a proper shopping action, a cashier removes the self-sounding tag alarm apparatus from the commodity after canceling the detecting mechanism of the alarm apparatus. Thus, no alarm is given in this case. This canceling operation is carried out mechanically with an alarm cancel key or a special jig.
The conventional alarm apparatus constructed as described above has the following disadvantage.
In the conventional apparatus, the mechanically operable alarm cancel key is inserted into a keyhole, or the special jig is fitted, to cancel the alarm by mechanically stopping the internal detecting mechanism. This alarm canceling operation is very troublesome, and tends to retard an accounting process.